Those all look really good. How about some sources?

 

Thanks for that - prompted me to go search and voila:

https://rennlist.com/forums/showthre...uri+turbulence

Includes a post by Erkka of a part of the WSM that does indeed indicate its for noise supression.

 

I have the type that uses the Mercedes tubes with a silicone joining section as seen in Post #9. The section is available in red, Blue and Black for $75 a pair plus shipping.

 

I think the Mercedes type tubes are a similar material to stock S4 - and though they may eventually get a little more brittle (as the stock ones do) - they should last a long time - that's what they were designed for...

The neoprene is rated for 300F and harsh chemical environments so I expect it will also last pretty well - I've had it on for about 2 years and it still looks new - cleans up really nicely too.

Go here : http://polycarbonate-plastic-resin.c...lass-2-Ply.htm I used the KH512 if I recall correctly. But note late airbox intakes are different than earlier ones - measure... The 12 foot length is enough to do 2 cars... since they only sell it in 12' lengths you have to in with someone. It looks neater with the end covers from the stock tubes (GTS only) - otherwise you have the spiral wire to end.. it wants to go tangential...

If you are worried about airflow - see how smooth the inside of GTS tubes are (and how crappy they look after about 10 years...)

 

I changed my GTS tubes for the aftermarket ones as I refuse to pay $200 each for the POS Porsche ones.
Just my 5 cents worth.